Samsung QD-OLED S90D / S94D vs TCL C855

In the HDR effect category, the Samsung S90D delivers remarkable performance. On the luminance graph for up to 10% of the window, the television surpasses the 1000 nits mark, which is a notable achievement. However, in the film scenes we tested, these values were slightly lower. In scenes with fullscreen sun glare the brightness drops to about 500 nits, but this is still considered a very good result. It is also worth noting that this model stands out due to its very high colour gamut coverage, thanks to the QD-OLED panel, giving it an edge over televisions with WOLED panels, which cannot achieve such a wide spectrum of colours.

The TCL C855 delivers a highly varied HDR effect. At times, the television truly excels, while at other moments, it appears reminiscent of a low-end model equipped with FALD backlighting. Inconsistency is frequently found with this brand, so it didn’t come as a surprise. The first and last scenes, which feature large light elements, are nothing short of spectacular, boasting brightness levels of 1470 and 1820 nits, respectively. Such brightness can make viewers squint their eyes, allowing them to feel the extraordinary dynamism of the scene. It genuinely immerses the audience, creating a sensation of being inside the movie itself. However, the situation shifts dramatically when small or subtle elements with high luminance appear against a dark background. In these instances, the TCL C855 significantly reduces brightness to levels as low as 240 nits to mitigate halo effects. This reduction is disappointing, as it can make the movie appear as if it was not filmed in HDR. Despite these shortcomings, the HDR effect on the TCL C855 enhances the viewing experience during dynamic scenes, making it feel more engaging and allowing the viewer to feel part of the action. Even with smaller high-luminance elements, the television retains details without excessive dimming. Additionally, the TCL C855 adjusts image brightness according to scenes with rich detail, further enhancing viewing comfort.

The Samsung 65" S90D with a QD-OLED panel has been tested in Filmmaker Mode, which the manufacturer has used for years to deliver optimal picture settings. In this mode, the TV offers a very good image, but there are some shortcomings worth noting.

In terms of white balance, viewers may notice a red dominance in HD content, which can make skin tones appear unnatural and create a warm overall scene, potentially affecting immersion. This issue becomes more apparent in scenes where subtle colour differences are important. The same effect can be observed in 4K HDR content, though the red shift is less pronounced. This shift can prevent certain details and colours from being fully realised, diminishing the naturalness of the image.

As for contrast, the gamma performance is decent but still has some issues. The gamma values fall short of the reference level of 2.4, resulting in bright areas of the image appearing washed out and dark areas lacking detail. This limitation can make certain scenes feel less dynamic and impact the depth and richness of the picture. However, the EOTF curve for contrast in 4K HDR content performs well, showing the TV's ability to handle differences in brightness. That said, these values still fall slightly below the ideal range, indicating room for further optimisation.

Overall, the Samsung S90D in Filmmaker Mode offers solid colour reproduction, but some adjustments are needed to fully unlock its potential, particularly with different types of content.

The best factory mode for the TCL C855 is the "Film" setting, and all our tests were conducted using this mode. However, like many predefined modes, it has flaws that should be addressed to achieve an image closer to the producer's original vision. In our examination of the colour characteristics for both SDR and HDR materials, issues were found.

Focusing first on SDR content, there is a noticeable dominance of green in the white balance, which leads to an unpleasant greenish tint across the entire image. The gamma chart, crucial for image contrast, shows a significant deviation from the reference line marked at 2.4. Initially, there is a pronounced spike in the measured value, resulting in an over-contrasted image where details can merge into a dark blob. This condition persists for nearly 20% of the chart before it dips below the reference line, causing the image to brighten and resulting in a substantial drop in contrast.

In HDR materials, the factory mode performs somewhat better; the white balance appears more balanced overall, although the green tint resurfaces in the latter half of the spectrum. When we look at the Electro-Optical Transfer Function (EOTF) curve—unlike gamma, which reflects contrast—we identify two main errors: the darkest scenes are too dark, while the brightest ones become overexposed. This discrepancy was evident in our review of the scene from the movie "Pan," further illustrating the TCL C855's HDR performance issues.

The quality improves more than anticipated after calibrating the S90D television in movie mode. The white balance for HD and 4K HDR content has been fine-tuned to near perfection. While minor imperfections are still noticeable, they are subtle enough not to significantly impact the overall picture quality. Colours have become more cohesive, promoting a natural reproduction of details, particularly in scenes where precise colour representation is essential. It’s important to note that this particular model, in this size, uses a QD-OLED panel, which offers a broader colour gamut compared to other versions of this model equipped with a WOLED panel.

The contrast has also seen a marked improvement. After calibration, the gamma chart is much closer to the expected curve, resulting in a better balance between the bright and dark areas of the image. The EOTF curve, which previously indicated issues with overexposed scenes, now shows significantly better results. This improvement allows for greater preservation of details in the brighter parts of the image, particularly in HDR content.

TCL, like most manufacturers, offers advanced calibration tools within its televisions. These include both 2-point and 20-point adjustments for grayscale, as well as a comprehensive colour management system. As a result, we achieved impressive results in SDR materials, bringing the image significantly closer to the reference standard. We successfully eliminated both the green tint and the gamma issue, although a slight "kink" at the very beginning of the gamma curve still persists.

In contrast, the situation with HDR materials was less favourable, as the TCL C855 did not allow for precise modelling. We were only able to make minor adjustments to the EOTF curve while significantly enhancing the overall colour accuracy. This limitation suggests that while calibration tools are effective, they may require further refinement for optimal HDR performance.

The television excels at smoothing tonal transitions, allowing colours to blend seamlessly, resulting in a natural and fluid image. The built-in noise reduction feature can further enhance these transitions, useful in certain situations. However, it is important to note that activating this option may overly smooth out the desired film grain structure, potentially compromising the authenticity and atmosphere of the image. Therefore, caution is advised when using this feature, to maintain the character and depth of the content.

The S90D model handles lower-resolution materials effectively, as demonstrated in the displayed image. The model's silhouette remains sharp and naturally reproduced, with fine details preserved. Additionally, the branches of the trees are well-defined, free from any visible jagged edges that might otherwise degrade the image quality. Thanks to efficient scaling, even lower-resolution content appears attractive on the screen, which is sure to please users who rely on a variety of content sources, such as standard cable or antenna television.

Once again, we will take a look at the function of smoothing tonal transitions, but this time also image scaling. The latter is particularly important when watching materials of lower quality, such as some television programs or older films. We will focus on the function responsible for tonal transitions. Interestingly, just like in the scenes from the previous test where it performed excellently and smoothed out practically all the inconsistencies, here it had issues. Using the menu responsible for the operation of this function, we found that no setting—even the strongest—was helpful.

Image scaling in TCL C855 is defined as one of the best we have had the opportunity to test so far. The image is sharp, but in a way that could be described as natural to our eye. Even small, fine branches do not have jagged edges, and there is no white halo around figures, a characteristic of weaker scaling systems.

The S90D TV, featuring a 120 Hz refresh rate matrix and up to 144 Hz in the appropriate PC configuration, delivers excellent motion fluidity. Samsung highlights a range of sharpness settings on a ten-point scale, allowing users to fine-tune the display to their preferences. In UFO tests, the OLED matrix showcases its strengths by eliminating any blurring. The ultra-fast pixel response ensures dynamic movements are faithfully reproduced.

Similar results can be seen in other sizes of this model with a WOLED matrix, which also offer outstanding image fluidity. Organic technology, in this case, is considered among the best on the market. The S90D image, regardless of the matrix type, is exceptionally sharp and detailed, making this television perfect for dynamic scenes, whether for gaming or sports broadcasts. Additionally, its refresh rate and sharpness capabilities guarantee that every movement is smooth and natural, satisfying even the most discerning users.

The maximum refresh rate you can set on the TCL C855 is 144 Hz. Naturally, this is only possible after connecting the TCL C855 TV to a very powerful PC. Otherwise, we will be operating at a maximum refresh rate of 120 Hz, which is recommended if we want to watch primarily sports or materials with a lot of motion dynamics. For those who require high image fluidity, the manufacturer has implemented a multi-stage motion smoother. It is divided into two separate sliders which control the sharpness of moving images (Motion Blur Reduction) and flicker (Flicker Reduction). Both sliders can be adjusted from 0 to 10, with each level affecting the degree of fluidity, so everyone can find their sweet spot. We present a setting that allows for slight smoothing without the soap opera effect. The matrix of the TCL C855 features a very good response time. This is particularly important since VA panels often struggle with the so-called ghosting effect, where a black halo can be observed behind a fast-moving object. where a black halo can be observed behind a fast-moving object.

The S90D television is an excellent solution for gamers, offering a range of advanced features that elevate gaming quality to a new level. Equipped with HDMI 2.1 standard, the model supports modern technologies such as VRR (Variable Refresh Rate) and ALLM (Auto Low Latency Mode). Thanks to these solutions, the image is incredibly smooth, and the response to commands is instantaneous, which is crucial in dynamic titles. Additionally, the S90D supports HLG (Hybrid Log-Gamma) as well as G-Sync and FreeSync image synchronisation. This enables a perfect connection with Xbox, PlayStation, or PC, eliminating issues with tearing and stuttering. The built-in operating system offers the Xbox Game Pass app, providing access to a vast library of games directly from the television. This solution makes gaming even more convenient and accessible. The Game Bar feature provides quick access to essential information, such as current settings, performance statistics, and the ability to adjust image options. This allows for on-the-fly display parameter modification, which is extremely useful during intense gameplay. Despite lacking support for Dolby Vision, the S90D still offers excellent HDR image quality, allowing for full utilization of the potential of games and movies. As a result, the S90D represents a unique combination of modern technologies, outstanding image quality, and intuitive features, perfect for any gaming enthusiast.

The TCL C855 TV has fully-featured HDMI 2.1 ports, boasting a full bandwidth of 48 Gb/s. During our testing, we confirmed the seamless operation of all functions included in this connection standard. As highlighted, all checkboxes are illuminated in green, a feature that will undoubtedly be appreciated by gamers, whether on consoles or those using the TV as a computer monitor. Additionally, the TCL C855 supports both AMD FreeSync and NVIDIA's G-Sync, which can be easily activated in the graphics card settings. Those with powerful configurations can feed a 144 Hz signal to the C855, which handles this effortlessly. It is also worth noting the implementation of the HGIG mode, which can be excessively bright due to the shortcomings of the "Game" mode, making proper configuration on the screen challenging. Fortunately, the TV excels with the Dolby Vision format.

TCL, as one of the pioneering manufacturers, has equipped its televisions with a special GameBar, allowing for extensive adjustment of settings "on the fly" without the need to exit the game. This feature includes options like an additional crosshair grid, black level correction, and settings designed for individuals with disabilities. The image showcases the next generation of this solution.

In summary, the TCL C855 TV is an ideal choice for those seeking a screen for all forms of electronic gaming. With comprehensive features supporting such entertainment, it provides an extremely engaging experience. It is also important to emphasise that it maintains very low input lag, regardless of the selected settings, including when using the Dolby Vision HDR format.